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No. 750,022. PATENTED JAN. 19, 1904. w. s. DEMPSEY.

METALLURGICAL FURNACE.

APPLICATION FILED DEC. 8. 1902.

N0 MODEL. 2 SHEETS-MEET 1.

' No. 750,022. PATENTED JAN. 19, 1904.

W. s. DEMPSEY. METALLURGICAL FURNACE.

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Patented January 19, 1904.

PATENT OFFICE.

WILLIAM S. DEMPSEY, OF NEW YORK, N. Y,

METALLURGICAL FURNACE.

SPECIFICATION forming part of Letters Patent No. 7 50,022, dated January19, 1904,

Application filed December 8,1902. Serial No. 134,264. (No model.)

To all whom it may concern.-

Be it known that I, WILLIAM S. DEMPsEY, a citizen of the United States,residing at New York city, county and State of New York, have inventedcertain new and useful Improvements in Metallurgical Furnaces, of whichthe following is a specification.

My invention relates to metallurgical furnaces, and more particularly tomeans for delivering and distributing air in suflicient quantity and atproper points to supply the oxygen necessary for the complete combustionof the gases in the working chamber, the object being to obtainincreased efficiency and effect greater economy in the consumption offuel.-

In the practical embodiment of my invention I provide, first, for therapid reduction of the fuel and disengagement of the gases by deliveringblasts of preheated air from points beneath the grate and direct thesame upward through the mass of incandescent fuel toward the side wallor in opposition to the outgoing current of gases to produce immediateand effective diffusion. For'the continued combustion of the half-burnedhydrocarbureted gases above the fire additional blasts of heated air aredelivered from suitable points in the front, rear, and side walls of thecombustion-chamber, and as the air is discharged in fine jets anintimate mixture with the gases follows before the temperature of' thecarbon thereof is reduced below the point of ignition. The blasts fromthe side wall of the furnace drive the gases from the combustion-chamberinto the working chamber, and the cross-blasts from the front and rearwalls in being directed transversely through the outgoing current .tendto break it up, and the air rapidly mixes with the heated gases in suchproportions as to effect practically their complete combustion in theworking chamber. To insure, however, against the escape of anyunconsumed heat-giving products and at the same .time renderthe-combustion smokeless, 1 pro- One embodiment of the invention isillus trated in the accompanying drawings, throughout the several viewsof which like numerals of reference indicate corresponding parts.

In the drawings, Figure 1 is a longitudinal sectional view illustratingthe application of my invention to a well-known type of metallurgicalfurnace, and Fig. 2 is a horizontal sectional view thereof.

Referring to the drawings, an ordinary heating-furnace is shown, 1indicating the inclosed ash-pit; 2, the grate; 3, the fuel-chamber,which is charged through the stoke-hole 3 in. the front wall; 4, thebridge dividing the fuel or combustion chamber and the working chamber;5, the hearth, to which the material to be heated is entered throughprotected openings 5 5 5, &c. in the front and rear walls, and 6 theflue leading to the chimney 6. The hearth is arched over in the usualmanner, so that the heat will be radiated from the arch upon the metal.

From a pipe 7 leading from a suitable source of supply, (not shown,) airunder pressure is delivered to pipes 8, 9, and 10, each ofwhich isprovided with a valve 8 9 10* for regulating the supply to the furnace.The air from pipe 8 is given a preliminary heating by being passedthrough 'a flat coil 8, embedded beneath the hearth, and is dischargedfrom two or more blast-pipes 8 8", projecting from the bridge-wall intothe inclosed ash-pit. These jets or blast-pipes are preferably given anupward inclination to direct the air through the grate-bars toward theside or end wall of the furnace, so as to distribute the same moreeffectively throughout the mass of fuel and render the combustionuniform over the entire grate-surface. By means of the valve 8 thedeliveryof the air for these blasts maybe varied as required. The pipe 9is connected in a similar manner with an air-heating coil 9T, extendingabove the furnace, and. which may be'either embedded in the brickwork orsupported thereon and protected by a covering of non-heat-conductingmaterial. The air from this coil is delivered to two or more jet orblast pipes 9 9, the samebeing preferably given a slight downwardinclination to discharge the air toward the bridge and drive the gasesfrom the combustion-chamber into the working chamber. These blasts maybe regulated by means of the valve 9. The pipe 10 is connected to supplytwo series of cross jets or blasts located, respectively, at pointsabove the bridge and adjacent to the chimney-flue.

The blasts 10 10 are delivered, preferably, from opposite points in thefront and rear walls of the furnace in the plane of the bridge asuitable distance above the same and are supplied from an air-heatingbox or chamber 10, located at one side of the bridge beneath the hearthand from which there is a connection 10 with the supply-pipe 10. Thesecond series of blasts 1O 10 located at opposite points in the frontand rear walls near the chimney-fiue, are supplied from pipe 10 throughan interposed heating-coil 10 embedded beneath the hearth. The supplyfor these two series of blasts may be regulated by means of the valve10.

As the operation will be generally understood from the foregoingdescription, I will describe the same briefly. In operating a furnace ofthe construction described it is first charged in the usual manner withgas-producing coal, and after a portion of the fuel has been raised to astate of incandescence the air for continuing the combustion is admittedat points beneath the grate fromaseries of blasts discharging into theinclosed ash-pit. These blasts are inclined so as to impinge upon andmix intimately with the mass of incandescent fuel upon the grate. Theforce of the blast through the fuel directed toward the side or end wallof the furnace in opposition to the outgoing current acts beneficiallyin promoting the intermixture of the combustible gases generated priorto their meeting with the supply of air for combustion at the entranceto the heating or working chamber. As both efficiency and economy dependlargely upon generating the heat in the locality where it is to beabsorbed-that is, in contact practically with the material to beheated-the gases in the combustion-chamber are driven into theheating-chamber by the force of the blasts 9 9, &c., controlled by thevalve 9. Bymeans of the cross-blasts at the bridge an additional supplyof air is admitted, which tends to break up the outgoing current ofgases and rapidly mixes with the same in such proportions as to effecttheir complete combustion in the working chamber. To prevent the escapeof any unconsumed combustible matter which may be carried along with theproducts of combustion, the flow is checked by the cross-blasts at theentrance to the chimney-flue, and the combustion is thus renderedcomplete by the resulting diffusion of air, the spent gases passing offthrough the chimney.

The main advantages of the invention consist, first, in a materialsaving in the consumption of fuel as a result of the united economyderived from the use of heated air and the regulation of the supply tothat which is consumed in eflecting complete combustion, and, second, toan increase in efficiency resulting from the facility for generating themost intense heat in the Working chamber or in the locality where it isto be absorbed.

It will be understood that I do not Wish to limit myself to the exactconstruction and arrangement shown, as various changes may be madewithout departing from the spirit and scope of my invention. Forexample, the invention may be readily applied to other types of furnaceand steam-jets substituted for the blast-pipes, it being immaterialwhether air or steam is employed. Other means may be employed forheating the air,or the coils might be differently arranged. The numberof valves might be increased to provide one for each blast-pipe, or bychanging the connections the number of valves employed might be reduced.Spraying-nozzles might be substituted for those shown, &c.; but all suchmodifications I consider obvious and immaterial variations of form andnot of substance and still within the meaning of the present invention.

Having therefore described my invention, I claim 1. In a metallurgicalfurnace the combination, of a working chamber and a combustionchamberopening into the same, oppositelydisposed blast-pipes below and abovethe grate in the combustion-chamber, the blasts above the grate beingarranged to drive the gases generated toward the working chamber and theblasts below the grate being directed angularly in an opposite directionto those above the grate, and cross-blasts within the working chamberdirected from the opposite sides of said chamber and backward toward thecombustion-chamber.

2. In a metallurgical furnace the combination, of a working chamber anda combustionchamber opening into the same, oppositelydisposedblast-pipes below and above the grate in the combustion-chamber, theblasts above the grate being arranged to drive the gases generatedtoward the working chamber and the blasts below the grate being directedangularly in an opposite direction to those above the grate, andcross-blasts within the working chamber directed from the opposite sidesof said chamber and backward toward the combustion-chamber together witha source of air-supply and means for preheating the air for the blasts.

3. In a metallurgical furnace the combination, in a heating-furnace, ofa working chamber and a combustion-chamber opening into the same,oppositely-disposed blast-pipes be low and above the grate in thecombustionchamber, the blasts above the grate being arranged to drivethe gases generated toward the working chamber and the blasts below thegrate being directed angularly in an opposite direction to those abovethe grate, and crossblasts at opposite ends within the working chamberdirected from the opposite sides of said chamber and backward toward thecombustion-chamber, together with a source of air-supply, heating-coilsinterposed between

